A group of seabirds relaxes on Tern Island in the Northwest Hawaiian Islands. (Photo: Duncan/Flickr)

The North Pacific Ocean is teeming with plastic, much of which swirls into the infamous Great Pacific Garbage Patch. But there's plenty to go around, and lots of drifting debris also gets tangled up in the region's network of coral reefs and atolls — especially the Northwestern Hawaiian Islands, which act like a fine-tooth comb for wayward trash.

One tiny island is so littered with plastic, in fact, it could become a federal hazardous waste site. The U.S. Environmental Protection Agency unveiled plans this week to investigate marine debris around Tern Island, a 25-acre speck about 550 miles northwest of Honolulu, as a first step toward declaring it a Superfund site. If that happens, it would be historic: The EPA has established hundreds of Superfund sites over the past 30 years for a variety of reasons, but none are on the list because of plastic pollution.

"It's great that the EPA is going to investigate the dangers to wildlife from plastic pollution," says Emily Jeffers, a staff attorney with environmental advocacy group the Center for Biological Diversity, in a press release. "Hawaiian monk seals, green sea turtles and seabirds beyond number are hurt and killed by the thousands of pounds of waste littering this beautiful island. We have to take action now."

The move was prompted by a year-old petition from the Center for Biological Diversity, which asked the EPA in December 2012 to study plastic pollution across a 1,200-mile stretch of the Northwest Hawaiian Islands, including "the waters of the Great Pacific Garbage Patch within United States jurisdiction." The EPA didn't agree to do that, but its Tern Island compromise could still push into uncharted waters — and possibly introduce a new tactic to help stem the planet's rising tide of marine debris.

Tern Island, which has hosted U.S. military facilities since World War II, is no stranger to pollution. Officials have had to remove asbestos and sewage from its aging buildings, and lately it has become a magnet for marine plastic. While other trash sinks or biodegrades, sunlight breaks plastic into tiny pieces without destroying it. Animals mistake these floating shards for food, and plastic often turns up in dead seabirds' stomachs. Larger debris like plastic bags and fishing nets also entangles rare monk seals and sea turtles.

But the EPA isn't trying to solve such broad problems with a Superfund listing. It's focusing on Tern Island because of a more specific threat: Monk seals there have elevated levels of polychlorinated biphenyls (PCBs), industrial chemicals that are toxic, carcinogenic and environmentally persistent. The U.S. outlawed PCB production in 1979, but as Honolulu Civil Beat reports, the EPA suspects it's entering the food chain via tiny bits of plastic.

When a storm damaged a seawall around Tern Island last year, it exposed an old landfill whose buried electrical equipment may contain PCBs and other contaminants, according to the EPA. And plastic isn't just dangerous to marine animals because it's indigestible — it can also absorb toxic chemicals from seawater, creating a sort of pollutant pill that's eaten by sea life and then "bioaccumulates" the toxins as they move up the food chain.

"The EPA intends to evaluate potential and observed releases of hazardous substances from Tern Island, including hazardous substances that absorb to plastic marine debris in the surrounding surface water," the EPA wrote in a Nov. 14 letter to the Center for Biological Diversity, according to the Los Angeles Times. The agency also noted the island "presents a scientifically meaningful opportunity to evaluate the potential toxicological impact of plastic marine debris ingestion on highly sensitive receptors."

Still, an EPA press officer tells the Times a Superfund designation for the island is "way far away," pointing out the investigation is just "a first step in the road."

That hasn't discouraged environmental advocates, though, who are already looking down the road in hopes the EPA inquiry will pave the way for broader solutions to marine debris.

"The EPA is taking a very important first step toward assessing the nature and extent of plastic pollution on Tern Island," Jeffers says. "We hope that what it learns from this investigation will lead to cleanup of the islands — and ultimately to policies that reduce the flow of garbage into our oceans."

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